Scales are widely used in point of sale (POS) systems, in order to weigh items, such as fruit and vegetables, being purchased. These scales comprise four support members arranged into a substantially rectangular support frame, which supports a flat plate onto which items to be weighed are placed. The plate tends to be made of a material, such as glass, which is transparent to radiation utilized to scan bar codes on items being purchased. The bar code scanner is placed in a well beneath the transparent plate. In this way the person operating the POS terminal can both weigh loose items and scan bar-coded items in the same work area.
In some POS systems such as self-checkout terminals a second scale is placed in the bag well in the terminal. This “security” scale is arranged to weigh all of the items placed in a bag in the bag well. This is compared to the weight expected for the items weighed in the first scale and the items scanned by the terminal barcode scanner. The weight of scanned items is entered into the POS control computer in order to facilitate this comparison. If the weight of items in the bag well exceeds the expected weight then a security alert can be activated in order to warn the store personnel of a possible theft or, at least, a misuse of the terminal.
However, the wells containing scanning apparatus and bag wells in different models of POS terminal can be quite different in size, which leads manufacturers to require to stock a variety of scales in order to fit scales into the various terminals. This is a significant financial and stock keeping problem for manufacturers.
Accordingly, it is a general object of the present invention to overcome or at least mitigate the problems experienced by manufacturers, as identified above.